The present invention relates to a centrifugal fan assembly, and more particularly to an improved centrifugal fan wheel.
Centrifugal fans or blowers are used to move air and/or other gases from one location to another. Typical centrifugal fan applications include air conditioning, ventilation and heating.
Essentially, a centrifugal fan assembly includes a centrifugal fan wheel mounted for rotation in a fan housing or casing. A motor assembly is included to drive the fan wheel. Air (or other flow medium) is drawn into the fan assembly through an inlet to the rotating fan wheel where it is radially accelerated for discharge at an outer extent of the fan wheel. The kinetic and potential energy developed as a result of the rotating action of the fan wheel provides sufficient energy to discharge the flow medium from the fan to the environment.
As air or other flow medium is forced through the fan wheel, the rotating action of the fan wheel is transferred to the air or flow stream as increased static pressure and velocity pressure. Static pressure is essentially a measure of the potential energy of the flow stream. Velocity pressure is a measure of the kinetic energy present in the moving gas stream.
Fan and fan wheel design have become increasingly significant as the cost of energy increases. It is desirable to design a fan or fan wheel which operates more efficiently. Fan efficiency is generally specified in terms of total (or mechanical) efficiency or in terms of static efficiency. Total (mechanical) efficiency is a measure of the total energy in the gas stream as a percentage of the energy input to the fan. Static efficiency relates to the static pressure increase of the flow stream relative to the energy input to the fan.
Thus, it is a continuing goal to design a fan or fan wheel having increased total (mechanical) and static efficiency than those previously constructed.